Due to advancements in telecommunications and data transmissions speeds over balanced, twisted-pair cables, the connectors (such as jacks, plugs, patch panels, cross connects, etc.) are a critical impediment to high performance data transmission at higher frequencies. Performance characteristics, particularly crosstalk and return loss, degrade beyond acceptable levels at higher frequencies. This degredation is particularly true for operation at category 6 and category 6a levels.
When an electric signal is carried on the signal line, which is in close proximity of another signal line or lines carrying a signal or signals, such as in the case of adjacent pins of contacts in the connector, energy from one signal line can be coupled onto adjacent signal line by the electric field generated by the potential between the two signal lines and the magnetic field generated as a result of the changing electrical fields. This coupling, whether capacitive or inductive, is called crosstalk when this phenomenon occurs between two or more signal lines.
Crosstalk is a noise signal and degenerates the signal-to-noise margin or ratio (SIN) of the system. In telecommunication systems, reduced S/N margins result in greater error rates in the information conveyed in the signal line. Depending on the category of the system, the S/N margin must satisfy set performance criteria.
Crosstalk problems could be overcome by increasing the spacing between the signal lines, or by shielding the individual signal lines. In many cases, the wiring is preexisting and standards define the geometries and pin definitions for connectors, making the necessary changes to such systems cost prohibited. In this specific case of communication systems using balanced, twisted-pair wiring, standards defining connector geometries and pin out definitions are in effect, but were created prior to the need for high speed data communications.
These standards have created a large base of wiring and connectors and a need for connectors capable of meeting the requirements of high speed communications, while maintaining compatibility with the original connectors. The standard connector geometries and pin outs are such that a great deal of crosstalk occurs at higher signal frequencies.
Numerous connector constructions have been developed to alleviate this crosstalk problem. Such systems involve counteracting a noise signal in a line by inducing in that line a signal equal to and opposite to the noise signal such that the induced noise signal is effectively cancelled by the induced correction signal. Examples of such connectors are disclosed in U.S. Pat. Nos. 5,432,484, 5,673,009 and 6,796,847, the subject matter of each of which is hereby incorporated by reference.
The distance from the circuitry providing the compensation for the crosstalk to the point of engagement of the plug contacts and the jack contacts has been determined to be significant in the effectiveness of reducing crosstalk. Such distances are to be made as small as possible. The distance between the plug contact-jack contact engagement point to the compensation circuitry also needs to be maintained constant, as well as as small as possible, to maintain consistent performance. Additionally, the jack contacts must remain in place despite flexing to avoid inadvertent contact with the other jack contacts or improper contact with the plug contacts. The resilient jack contacts must maintain their resiliency, and must not be overstressed by the deformation caused by engagement with the plug.
As used in this application, the terms “top”, “bottom”, “side”, “front”, “rear” and the like are intended to facilitate the description of the electrical connector and parts thereof. Such terms are merely illustrative of the connector and its parts, and are not intended to limit the electrical connector and its parts to any specific orientation.